CHAPTER ONE
INTRODUCTION
Background of the study
The scientific names of fungi that grow on bread are; Rhizopus nigricans and Mucor stolonifer (Banwart, 2004). There are minor differences between the two and both are commonly referred to as “Bread mold‟. These are invariably the first one to “arrive” and germinate on a piece of bread. Later, many others may follow such as Aspergillus and Penicillium (Hocky, 2008). Yeast is used in the dough of the bread to release CO2 and makes the bread spongy and fluffy. Bread is one of the oldest prepared foods.
Evidence from 30,000 years ago in Europe revealed starch residue on rocks used for pounding plants. It is possible that during this time, starch extract from the roots of plants, such as cattails and ferns, was spread on a flat rock, placed over a fire and cooked into a primitive form of flatbread. Around 10,000 BC, with the dawn of the Neolithic age and the spread of agriculture, grains became the mainstay of making bread. Yeast spores are ubiquitous, including the surface of cereal grains so any dough left to rest will become naturally leavened. There were multiple sources of leavening available for early bread. Airborne yeasts could be harnessed by leaving uncooked dough exposed to air for some time before cooking. Pliny the Elder reported that the Gaul’s and Iberians used the foam skimmed from beer used a paste composed of grape juice and flour that was allowed to begin fermenting, or wheat bran steeped in wine, as a source for yeast.
The most common source of leavening was to retain a piece of dough from the previous day to use as a form of sourdough starter ( Seiler, 2000). In 1961, the Chorleywood bread process was developed, which used the intense mechanical working of dough to dramatically reduce the fermentation period and the time taken to produce a loaf. The process, whose high energy mixing allows for the use of lower protein grain, is now widely used around the world in large factories. As a result, bread can be produced very quickly at low costs to the manufacturer and the consumer.
STATEMENT OF PROBLEM
The spoilage of bread due to decay most times limits its availability to consumers and causes economic waste to bakery owners. Bread is mostly spoiled by fungi. The isolation and identification of these decay organisms will go a long way to profer solution on matter how little to this problem of bread decay.
AIM AND OBJECTIVES OF THE STDU
The aim of this study is to isolate and identify Rhizopus and other fungi associated with bread decay.
SPECIFIC OBJECTIVES ARE
i. To isolate and identify bacterial contaminants from bread decay
ii. To isolate and characterize fungal contaminants from bread decay
SIGNIFICANCE OF STUDY
The study will help in the acquisition of the knowledge of Rhizopus from bread decay and fungi associated in the bread decay
LIMITATION OF THE STUDY
This work is limited to viable microorganism present in the bread decay only.